//+-------------------------------------------------------------------------
//
// Copyright (C) 1994-1997, Microsoft Corporation.
//
// File: rowseek.cxx
//
// Contents: Classes which encapsulate a positioning operation
// for a table.
//
// Classes: CRowSeekDescription
// CRowSeekNext
// CRowSeekAt
// CRowSeekAtRatio
// CRowSeekByBookmark
//
// History: 06 Apr 1995 AlanW Created
//
//--------------------------------------------------------------------------
#include <pch.cxx>
#pragma hdrstop
#include <query.hxx>
#include <sizeser.hxx>
#include "tabledbg.hxx"
#include "rowseek.hxx"
//+---------------------------------------------------------------------------
//
// Member: CRowSeekDescription::MarshalledSize, public
//
// Synopsis: Return Serialized size of a CRowSeekDescription structure
//
// Arguments: - none -
//
// Returns: unsigned - size in bytes of serialized structure.
//
// Notes: The returned size should be the maximum of the serialized
// size on input and output. None of the seek descriptions
// grow on output, so the input size may be larger than the
// output size.
//
// History: 02 May 1995 AlanW Created
//
//----------------------------------------------------------------------------
unsigned
CRowSeekDescription::MarshalledSize(
) const {
//
// Determine the size of the serialized seek description
//
CSizeSerStream stmSize;
Marshall(stmSize);
return stmSize.Size();
}
//+---------------------------------------------------------------------------
//
// Member: CRowSeekDescription::MarshallBase, public
//
// Synopsis: Serialize the base CRowSeekDescription structure
//
// Arguments: [stm] -- stream structure is serialized into
// [eType] -- type descriminator for derived class
//
// Returns: nothing
//
// History: 29 Jan 1995 AlanW Created
//
//----------------------------------------------------------------------------
void
CRowSeekDescription::MarshallBase(
PSerStream & stm,
DWORD eType
) const {
stm.PutULong(eType);
stm.PutULong(GetChapter());
}
//+---------------------------------------------------------------------------
//
// Member: CRowSeekNext::Marshall, public
//
// Synopsis: Serialize a CRowSeekNext structure
//
// Arguments: [stm] -- stream structure is serialized into
//
// Returns: nothing
//
// History: 29 Jan 1995 AlanW Created
//
//----------------------------------------------------------------------------
void
CRowSeekNext::Marshall(
PSerStream & stm
) const {
CRowSeekDescription::MarshallBase( stm, eRowSeekCurrent );
stm.PutULong(GetSkip());
}
//+---------------------------------------------------------------------------
//
// Member: CRowSeekAt::Marshall, public
//
// Synopsis: Serialize a CRowSeekAt structure
//
// Arguments: [stm] -- stream structure is serialized into
//
// Returns: nothing
//
// History: 29 Jan 1995 AlanW Created
//
//----------------------------------------------------------------------------
void
CRowSeekAt::Marshall(
PSerStream & stm
) const {
CRowSeekDescription::MarshallBase( stm, eRowSeekAt );
stm.PutULong(Bmk());
stm.PutLong(Offset());
stm.PutULong(ULONG(_hRegion));
}
//+---------------------------------------------------------------------------
//
// Member: CRowSeekAtRatio::Marshall, public
//
// Synopsis: Serialize a CRowSeekAtRatio structure
//
// Arguments: [stm] -- stream structure is serialized into
//
// Returns: nothing
//
// History: 29 Jan 1995 AlanW Created
//
//----------------------------------------------------------------------------
void CRowSeekAtRatio::Marshall( PSerStream & stm) const
{
CRowSeekDescription::MarshallBase( stm, eRowSeekAtRatio );
stm.PutULong(RatioNumerator());
stm.PutULong(RatioDenominator());
stm.PutULong(ULONG(_hRegion));
}
//+---------------------------------------------------------------------------
//
// Member: CRowSeekByBookmark::Marshall, public
//
// Synopsis: Serialize a CRowSeekByBookmark structure
//
// Arguments: [stm] -- stream structure is serialized into
//
// Returns: nothing
//
// Notes: When serializing ByBookmarks, we only do bookmarks
// or statuses, not both. Only one must exist in the structure.
//
// History: 29 Jan 1995 AlanW Created
//
//----------------------------------------------------------------------------
void CRowSeekByBookmark::Marshall(PSerStream & stm) const
{
Win4Assert(_cBookmarks == 0 || _cValidRet == 0);
CRowSeekDescription::MarshallBase( stm, eRowSeekByBookmark );
stm.PutULong(_cBookmarks);
for (unsigned i = 0; i < _cBookmarks; i++)
stm.PutULong(_aBookmarks[i]);
stm.PutULong(_cValidRet);
for (i = 0; i < _cValidRet; i++)
stm.PutULong(_ascRet[i]);
}
//+---------------------------------------------------------------------------
//
// Member: CRowSeekNext::CRowSeekNext, public
//
// Synopsis: DeSerialize a CRowSeekNext structure
//
// Arguments: [stm] -- input stream structure is read from
// [iVersion] -- input stream version
//
// Returns: nothing
//
// History: 06 Apr 1995 AlanW Created
//
//----------------------------------------------------------------------------
CRowSeekNext::CRowSeekNext( PDeSerStream & stm, int iVersion ) :
CRowSeekDescription( eRowSeekCurrent, 0 )
{
SetChapter( stm.GetULong() );
SetSkip( stm.GetULong() );
}
//+---------------------------------------------------------------------------
//
// Member: CRowSeekAt::CRowSeekAt, public
//
// Synopsis: DeSerialize a CRowSeekAt structure
//
// Arguments: [stm] -- input stream structure is read from
//
// Returns: nothing
//
// History: 06 Apr 1995 AlanW Created
//
//----------------------------------------------------------------------------
CRowSeekAt::CRowSeekAt( PDeSerStream & stm, int iVersion ) :
CRowSeekDescription( eRowSeekAt, 0 )
{
SetChapter( stm.GetULong() );
_bmkOffset = stm.GetULong();
_cRowsOffset = stm.GetLong();
_hRegion = (HWATCHREGION) stm.GetULong();
}
//+---------------------------------------------------------------------------
//
// Member: CRowSeekAtRatio::CRowSeekAtRatio, public
//
// Synopsis: DeSerialize a CRowSeekAtRatio structure
//
// Arguments: [stm] -- input stream structure is read from
//
// Returns: nothing
//
// History: 06 Apr 1995 AlanW Created
//
//----------------------------------------------------------------------------
CRowSeekAtRatio::CRowSeekAtRatio( PDeSerStream & stm, int iVersion ) :
CRowSeekDescription( eRowSeekAtRatio, 0 )
{
SetChapter( stm.GetULong() );
_ulNumerator = stm.GetULong();
_ulDenominator = stm.GetULong();
_hRegion = (HWATCHREGION) stm.GetULong();
}
//+---------------------------------------------------------------------------
//
// Member: CRowSeekByBookmark::CRowSeekByBookmark, public
//
// Synopsis: DeSerialize a CRowSeekByBookmark structure
//
// Arguments: [stm] -- input stream structure is read from
//
// Returns: nothing
//
// History: 06 Apr 1995 AlanW Created
//
//----------------------------------------------------------------------------
CRowSeekByBookmark::CRowSeekByBookmark( PDeSerStream & stm, int iVersion ) :
CRowSeekDescription( eRowSeekByBookmark, 0 ),
_aBookmarks( 0 ),
_ascRet( 0 )
{
SetChapter( stm.GetULong() );
_cBookmarks = stm.GetULong();
if (_cBookmarks)
{
// Protect agains unreasonable requests, which probably are attacks
if ( _cBookmarks >= 65536 )
THROW( CException( E_INVALIDARG ) );
_aBookmarks = new CI_TBL_BMK [ _cBookmarks ];
for (unsigned i = 0; i < _cBookmarks; i++)
_aBookmarks[i] = stm.GetULong();
}
_maxRet = _cValidRet = stm.GetULong();
if (_cValidRet)
{
// Protect against unreasonable requests, which probably are attacks
if ( _cValidRet >= 65536 )
THROW( CException( E_INVALIDARG ) );
_ascRet = new SCODE [ _cValidRet ];
for (unsigned i = 0; i < _cValidRet; i++)
_ascRet[i] = stm.GetULong();
}
//
// We don't expect both bookmarks and statuses.
//
Win4Assert(_cBookmarks == 0 || _cValidRet == 0);
}
//+---------------------------------------------------------------------------
//
// Member: CRowSeekByBookmark::~CRowSeekByBookmark, public
//
// Synopsis: Destroy a CRowSeekByBookmark structure
//
// Returns: nothing
//
// History: 29 Jan 1995 AlanW Created
//
//----------------------------------------------------------------------------
CRowSeekByBookmark::~CRowSeekByBookmark( )
{
delete _aBookmarks;
delete _ascRet;
}
//+-------------------------------------------------------------------------
//
// Member: CRowSeekNext::GetRows, public
//
// Synopsis: Retrieve row data for a table cursor
//
// Arguments: [rCursor] - the cursor to fetch data for
// [rTable] - the table from which data is fetched
// [rFetchParams] - row fetch parameters and buffer pointers
// [pSeekDescOut] - pointer to seek description for restart
//
// Returns: SCODE - the status of the operation.
//
// Notes:
//
// History: 07 Apr 1995 Alanw Created
//
//--------------------------------------------------------------------------
SCODE
CRowSeekNext::GetRows(
CTableCursor& rCursor,
CTableSource& rTable,
CGetRowsParams& rFetchParams,
XPtr<CRowSeekDescription>& pSeekDescOut) const
{
LONG cRowsToSkip = GetSkip();
if (cRowsToSkip)
{
tbDebugOut(( DEB_IWARN, "CRowSeekNext::GetRows - non-zero skip count %d\n",
cRowsToSkip ));
}
WORKID widStart;
if ( rTable.IsFirstGetNextRows() )
{
//
// For the first GetNextRows call, the start position is
// beginning of table if cRowsToSkip is positive, and end
// of table if its negative. For subsequent calls, the
// current position is the start position.
//
if ( cRowsToSkip >= 0 )
widStart = WORKID_TBLBEFOREFIRST;
else
widStart = WORKID_TBLAFTERLAST;
}
else
widStart = rTable.GetCurrentPosition( GetChapter() );
WORKID widEnd = widStart;
//
// OffsetSameDirFetch implements the skip of one row that
// Oledb::GetNextRows requires on the first fetch
// when scrolling and fetching are in the same direction,
// and for subsequent fetches when the fetch is in the
// same direction as previous fetch. When the direction is
// reversed the first wid fetched is same as the last wid
// returned from the previous call, and offsetSameDirFetch
// is 0 in this case.
//
LONG offsetSameDirFetch = 0;
if ( rTable.IsFirstGetNextRows() )
{
if ( cRowsToSkip >= 0 && rFetchParams.GetFwdFetch() )
offsetSameDirFetch = 1;
else if ( cRowsToSkip < 0 && !rFetchParams.GetFwdFetch() )
offsetSameDirFetch = -1;
}
else
{
if ( rFetchParams.GetFwdFetch() == rTable.GetFwdFetchPrev() )
{
if ( rFetchParams.GetFwdFetch() )
offsetSameDirFetch = 1;
else
offsetSameDirFetch = -1;
}
}
SCODE scRet = rTable.GetRowsAt( 0, // no watch region
widStart,
GetChapter(),
cRowsToSkip + offsetSameDirFetch,
rCursor.GetBindings(),
rFetchParams,
widEnd );
//
// Don't attempt to save the widEnd if the positioning
// operation got us past the end of the table. Storing
// widEnd in rCursor will cause us to be stuck at the
// end, with no way to get any more rows. In this situation,
// we don't expect to have successfully transferred any rows.
//
// NOTE: don't throw, the error may need to be seen by caller
// in CRowset::_FetchRows
//
if ( WORKID_TBLAFTERLAST == widEnd ||
WORKID_TBLBEFOREFIRST == widEnd ||
( scRet == DB_E_BADSTARTPOSITION && cRowsToSkip == 0 ) )
{
Win4Assert(rFetchParams.RowsTransferred() == 0);
return DB_S_ENDOFROWSET;
}
if (SUCCEEDED(scRet))
{
rTable.SetCurrentPosition( GetChapter(), widEnd );
rTable.SetFwdFetchPrev( rFetchParams.GetFwdFetch() );
rTable.ResetFirstGetNextRows();
}
else
{
tbDebugOut(( DEB_WARN, "CRowSeekNext::GetRows failed, sc=%x\n",
scRet ));
}
if (DB_S_BLOCKLIMITEDROWS == scRet)
{
Win4Assert(rFetchParams.RowsTransferred() > 0);
pSeekDescOut.Set(new CRowSeekNext(GetChapter(), 0) );
}
return scRet;
}
//+-------------------------------------------------------------------------
//
// Member: CRowSeekAt::GetRows, public
//
// Synopsis: Retrieve row data for a table cursor
//
// Arguments: [rCursor] - the cursor to fetch data for
// [rTable] - the table from which data is fetched
// [rFetchParams] - row fetch parameters and buffer pointers
// [pSeekDescOut] - pointer to seek description for restart
//
// Returns: SCODE - the status of the operation.
//
// Notes:
//
// History: 07 Apr 1995 Alanw Created
//
//--------------------------------------------------------------------------
SCODE
CRowSeekAt::GetRows(
CTableCursor& rCursor,
CTableSource& rTable,
CGetRowsParams& rFetchParams,
XPtr<CRowSeekDescription>& pSeekDescOut) const
{
WORKID widStart = Bmk();
LONG iRowOffset = Offset();
SCODE scRet = rTable.GetRowsAt( _hRegion,
widStart,
GetChapter(),
iRowOffset,
rCursor.GetBindings(),
rFetchParams,
widStart );
// The first fetch took care of the hRegion manipulation
// set the new seek descriptor's hRegion to 0
if (DB_S_BLOCKLIMITEDROWS == scRet)
{
Win4Assert(rFetchParams.RowsTransferred() > 0);
pSeekDescOut.Set(new CRowSeekAt(0,
GetChapter(),
rFetchParams.GetFwdFetch() ? 1 : -1,
widStart) );
}
return scRet;
}
//+-------------------------------------------------------------------------
//
// Member: CRowSeekAtRatio::GetRows, public
//
// Synopsis: Retrieve row data for a table cursor
//
// Arguments: [rCursor] - the cursor to fetch data for
// [rTable] - the table from which data is fetched
// [rFetchParams] - row fetch parameters and buffer pointers
// [pSeekDescOut] - pointer to seek description for restart
//
// Returns: SCODE - the status of the operation.
//
// Notes:
//
// History: 07 Apr 1995 Alanw Created
//
//--------------------------------------------------------------------------
SCODE
CRowSeekAtRatio::GetRows(
CTableCursor& rCursor,
CTableSource& rTable,
CGetRowsParams& rFetchParams,
XPtr<CRowSeekDescription>& pSeekDescOut) const
{
WORKID widRestart = widInvalid;
SCODE scRet = rTable.GetRowsAtRatio( _hRegion,
RatioNumerator(),
RatioDenominator(),
GetChapter(),
rCursor.GetBindings(),
rFetchParams,
widRestart );
// The first fetch took care of the hRegion manipulation
// set the new seek descriptor's hRegion to 0
if (DB_S_BLOCKLIMITEDROWS == scRet)
{
Win4Assert(rFetchParams.RowsTransferred() > 0);
pSeekDescOut.Set(new CRowSeekAt(0, GetChapter(), 1, widRestart) );
}
return scRet;
}
//+-------------------------------------------------------------------------
//
// Member: CRowSeekByBookmark::GetRows, public
//
// Synopsis: Retrieve row data for a table cursor
//
// Arguments: [rCursor] - the cursor to fetch data for
// [rTable] - the table from which data is fetched
// [rFetchParams] - row fetch parameters and buffer pointers
// [pSeekDescOut] - pointer to seek description for restart
//
// Returns: SCODE - the status of the operation.
//
//
// History: 07 Apr 1995 Alanw Created
//
//--------------------------------------------------------------------------
SCODE
CRowSeekByBookmark::GetRows(
CTableCursor& rCursor,
CTableSource& rTable,
CGetRowsParams& rFetchParams,
XPtr<CRowSeekDescription>& pSeekDescOut) const
{
unsigned cFailed = 0;
ULONG cSavedRowsReq = rFetchParams.RowsToTransfer();
Win4Assert(_cBookmarks > 0);
Win4Assert(cSavedRowsReq <= _cBookmarks);
Win4Assert(0 == rFetchParams.RowsTransferred() && cSavedRowsReq > 0);
rFetchParams.SetRowsRequested(0);
SCODE scRet = S_OK;
TRY
{
XPtr<CRowSeekByBookmark> pSeekOut(
new CRowSeekByBookmark(GetChapter(), _cBookmarks) );
BOOL fFailed = FALSE;
// Iterate over bookmarks, calling rTable.GetRowsAt for each
for (unsigned i = 0; i < cSavedRowsReq; i++)
{
if (! fFailed)
rFetchParams.IncrementRowsRequested( );
WORKID widNext = _aBookmarks[i];
if (widNext == widInvalid)
{
scRet = DB_E_BADBOOKMARK;
}
else
{
TRY
{
scRet = rTable.GetRowsAt( 0, // no watch region
widNext,
GetChapter(),
0,
rCursor.GetBindings(),
rFetchParams,
widNext );
}
CATCH( CException, e )
{
scRet = e.GetErrorCode();
Win4Assert( scRet != STATUS_ACCESS_VIOLATION &&
scRet != STATUS_NO_MEMORY );
}
END_CATCH;
if (! SUCCEEDED(scRet) && scRet != STATUS_BUFFER_TOO_SMALL )
scRet = DB_E_BOOKMARKSKIPPED;
}
if (scRet == DB_S_ENDOFROWSET)
scRet = S_OK;
if ( STATUS_BUFFER_TOO_SMALL == scRet ||
DB_S_BLOCKLIMITEDROWS == scRet )
{
scRet = DB_S_BLOCKLIMITEDROWS;
break;
}
//
// set per-row error status
//
pSeekOut->_SetStatus(i, scRet);
if (FAILED(scRet))
{
cFailed++;
fFailed = TRUE;
}
else
fFailed = FALSE;
}
pSeekDescOut.Set( pSeekOut.Acquire() );
}
CATCH( CException, e )
{
scRet = e.GetErrorCode();
}
END_CATCH;
if (cFailed)
return DB_S_ERRORSOCCURRED;
else if (0 == rFetchParams.RowsTransferred())
return STATUS_BUFFER_TOO_SMALL;
else
return S_OK;
}
//+-------------------------------------------------------------------------
//
// Member: CRowSeekByBookmark::_SetStatus, private
//
// Synopsis: Set row status for a bookmark lookup
//
// Arguments: [iBmk] - index of bookmark to set status for
// [scRet] - the status to be saved
//
// Returns: Nothing
//
// History: 12 Apr 1995 Alanw Created
//
//--------------------------------------------------------------------------
void
CRowSeekByBookmark::_SetStatus(
unsigned iBmk,
SCODE scRet
) {
Win4Assert( iBmk < _maxRet );
if (_ascRet == 0)
_ascRet = new SCODE[_maxRet];
_ascRet[iBmk] = scRet;
if (iBmk >= _cValidRet)
{
Win4Assert( iBmk == _cValidRet );
_cValidRet = iBmk + 1;
}
}
//+-------------------------------------------------------------------------
//
// Member: CRowSeekDescription::MergeResults, public
//
// Synopsis: Update seek description state after a transfer
//
// Arguments: [pRowSeek] - row seek description after transfer
//
// Returns: Nothing
//
// Notes: Used only in user mode. Does nothing for CRowSeekNext,
// CRowSeekAt and CRowSeekAtRatio.
//
// History: 02 May 1995 Alanw Created
//
//--------------------------------------------------------------------------
void
CRowSeekDescription::MergeResults(
CRowSeekDescription * pRowSeek )
{
return;
}
//+-------------------------------------------------------------------------
//
// Member: CRowSeekByBookmark::MergeResults, public
//
// Synopsis: Update seek description state after a transfer
//
// Arguments: [pRowSeek] - row seek description after transfer
//
// Returns: Nothing
//
// Notes: Used only in user mode. Transfers statuses into
// original rowseek and bookmarks from original to
// result rowseek.
//
// History: 02 May 1995 Alanw Created
//
//--------------------------------------------------------------------------
void
CRowSeekByBookmark::MergeResults(
CRowSeekDescription * pRowSeekDesc)
{
Win4Assert(pRowSeekDesc->IsByBmkRowSeek());
CRowSeekByBookmark* pRowSeek = (CRowSeekByBookmark*) pRowSeekDesc;
Win4Assert(_cBookmarks > 0 &&
pRowSeek->_cValidRet > 0 && pRowSeek->_cBookmarks == 0);
//
// Transfer return statuses to this object from the other
//
unsigned iBaseRet = _cValidRet;
for (unsigned i=0; i < pRowSeek->_cValidRet; i++)
{
_SetStatus( i+iBaseRet, pRowSeek->_ascRet[i] );
}
delete [] pRowSeek->_ascRet;
pRowSeek->_ascRet = 0;
pRowSeek->_cValidRet = pRowSeek->_maxRet = 0;
//
// Transfer bookmarks from this object to the other.
//
if (_cBookmarks - _cValidRet > 0)
{
pRowSeek->_cBookmarks = _cBookmarks - _cValidRet;
pRowSeek->_aBookmarks = new CI_TBL_BMK[ pRowSeek->_cBookmarks ];
for (unsigned i=0; i<pRowSeek->_cBookmarks; i++)
{
pRowSeek->_aBookmarks[i] = _aBookmarks[ i+_cValidRet ];
}
}
}